Anti-microbial antibodies in celiac disease: Trick or treat?

Table 1 Frequency of anti-microbial antibodies in 190 patients with celiac disease and in control groups n (%)

	Group 1	Group 2	Group 3	Control	GI control
n	82	33	75	100	48
TGA IgA (U/mL) (median; IQR)	54.3 (20.2-100.0)	32.2 (9.9-73.1)	2.7 (2.2-3.7)	–	–
gASCA IgG positive	32 (39.0)bfj	12 (36.3)dfl	10 (13.3)	14 (14)	2 (4.2)
AMCA IgG positive	29 (35.4)bfjn	3 (9.1)	1 (1.3)	0 (0)	0 (0)
ALCA IgG positive	7 (8.5)	0 (0)	0 (0)	6 (6)	1 (2.1)
ACCA IgA positive	31 (37.8)bfjn	4 (12.1)	3 (4.2)	6 (6)	1 (2.1)
Any glycan positive	54 (65.9)bfjp	15 (45.4)dfl	15 (20)	21 (21)	4 (8.4)
Anti-OMP IgA positive	22 (26.8)	11 (33.3)	23 (30.7)	20 (20)	11 (22.9)

TGA: Antibodies against transglutaminase; Group 1: Celiac patients at the time of diagnosis; Group 2: Celiac patients after starting a gluten-free diet but still with celiac antibody positivity; Group 3: Celiac patients on a long-term strict gluten-free diet; Control: Healthy control; GI control: Non-celiac gastrointestinal disease control. Cut-off levels used for the determination of positivity were according to the manufacturers’ guidelines: 50, 100, 60, 90 U/mL and 25 U/mL for gASCA IgG, AMCA IgG, ALCA IgG, ACCA IgA, and anti-OMP IgA, respectively.

^bP < 0.001,

^dP < 0.01, group 1 or Group 2 vs control;

^fP < 0.001, group 1 or Group 2 vs GI control;

^jP < 0.001,

^lP < 0.01, group 1 or Group 2 vs Group 3;

ⁿP < 0.001,

^pP < 0.03, group 1 vs Group 2. Using χ²-test with Yates correction.

Table 2 Predictive power of serological markers for distinguishing between patients with celiac disease at the time of diagnosis and various control groups

	Sensitivity (%)	Specificity (%)	95% CI
			LR+	LR-
Celiac disease vs healthy controls
gASCA	39	86	2.73 (1.57-4.76)	0.71 (0.59-0.86)
AMCA	35	100	-	-
ACCA	38	94	6.36 (2.76-14.4)	0.66 (0.56-0.79)
Any glycans	66	79	3.13 (2.08-4.73)	0.43 (0.31-0.59)
Celiac disease vs non-celiac gastrointestinal controls
gASCA	39	96	9.36 (2.35-37.4)	0.64 (0.53-0.76)
AMCA	35	100	-	-
ACCA	38	98	18.1 (2.56-128.5)	0.64 (0.53-0.76)
Any glycans	66	92	7.90 (3.05-20.4)	0.37 (0.27-0.51)

Table 3 Association between the titer of anti-microbial antibodies and the leading clinical symptoms at the time of celiac disease presentation (in Group 1, n = 78¹)

	Malabsorption	Non-specific gastrointestinal	Anaemia
n	32	34	9
gASCA IgG	54.8 (16.4-99.4)b	21.3 (7.1-76.5)	12.2 (8.8-36.7)
AMCA IgG	90.3 (59.5-115.9)b	73.8 (52.3-104.4)a	44.1 (25.1-55.0)
ALCA IgG	20.6 (16.7-31.2)b	23.7 (16.5-39.1)a	12.8 (9.9-15.2)
ACCA IgA	103.8 (53.3-192.1)b	57.3(37.4-100.5)a	26.8 (12.7-53.6)
OMP IgA	14.8 (5.2-33.2)	15.2 (8.2-24.2)	16.2 (2.9-34.1)

¹Detailed clinical data were not available for 4 patients, data of 3 patients with other symptoms are not shown;

^aP < 0.005,

^bP < 0.01, between patients with non-specific gastrointestinal symptoms or malabsorption and anaemia by t-test for independent samples with separate variance estimates.

Table 4 Occurrence of multiple antibody responses to microbial antigens in untreated celiac disease patients in relation to the number of responses against microbial antigens n (%) (n = 78)

	0	1	2 to 4	Total
Severe malabsorption	7 (22)	8 (25)	17 (53)	32 (40)
Non-specific gastrointestinal symptoms	13 (38)	12 (35)	9 (27)	34 (44)
Iron deficiency anemia	6 (67)	3 (33)	0	9 (12)
Others	2	0	1	3 (4)
Total	28 (36)	23 (29)	27 (35)	78 (100)

P = 0.019 by χ²-test. Clinical data were not available for 4 patients.